Complex, localized changes in CO₂ assimilation and starch content associated with the susceptible interaction between cucumber mosaic virus and a cucurbit host

Abstract

SummaryInfection of the cotyledons of Cucurbita pepo L. with cucumber mosaic virus (CMV) results in the formation of chlorotic, starch-containing lesions. To characterize the physiological changes occurring within lesions, the distribution of the virus was examined by immunolocalization and correlated with starch accumulation, 14CO2 assimilation and chlorophyll a fluorescence quenching. These techniques resolved the lesion into a complex and reproducible arrangement of cell types of diveree physiology. The region of infected cells extended beyond specific circular zones of cells which variously showed enhanced rates of CO2 assimilation, enhanced chlorophyll a fluorescence quenching, starch accumulation, starch degradation and chlorosis. This indicates a series of physiological changes occurring over several days following viral replication within a cell. Starch accumulation in the lesion was shown to result from photosynthetic activity of cells within the lesion and not from the import of photosynthate from surrounding uninfected areas of the cotyledon.

Cucumber Mosaic Virus Infection Affects Sugar Transport in Melon Plants

“…Numerous reports have indicated that carbohydrate metabolism in the source leaf is influenced by viral infection (Tecsi et al, 1994a(Tecsi et al, , 1994b(Tecsi et al, , 1996. Infected source leaves are usually characterized by reduced photosynthetic rate, a decrease in the concentration of soluble sugars, and often starch accumulation (Goodman et al, 1986;Fraser, 1987).…”

“…Detailed analysis of the host response to cucumber mosaic virus (CMV) infection was performed in cotyledons of marrow (Cucurbita pepo L.) plants (Tecsi et al, 1994a(Tecsi et al, , 1994b). An increase in starch and a decrease in Suc contents were observed during the first few days after infection.…”

Estudio de la interacción entre naranjo amargo y el virus de la tristeza de los cítricos

“…Diferencias en los procesos metabólicos entre los tejidos sanos e infectados por virus, incluyendo el metabolismo de lípidos y azúcares, los niveles de fotosíntesis, respiración y transpiración, han sido descritas previamente (Matthews, 1991). Técsi et al (1994) observaron que después de la infección viral aumentaba la capacidad fotosintética de las células contiguas a las células infectadas, lo que iba acompañado de una acumulación de almidón inmediatamente detrás del frente de la infección. Estos autores concluyeron que el aumento en la capacidad de fotosíntesis proporcionaba la fuente necesaria de carbono para soportar la síntesis de los productos virales y observaron que categorías funcionales relacionadas con la biosíntesis de la pared celular también se encontraban activadas (Técsi et al, 1996).…”

“…En distintos estudios se ha observado que el desarrollo de la sintomatología va asociado con una represión de los genes relacionados con la pared celular (Shimizu et al, 2007;Yang et al, 2007;Babu et al, 2008). La clorosis característica de las hojas con el síndrome de SY podría ser debida en parte a una reducción en esta etapa de la expresión de genes relacionados con el metabolismo de los azucares e indirectamente con la fotosíntesis (Técsi et al, 1994(Técsi et al, , 1996Maule et al, 2002;Pompe-Novak et al, 2005;Espinoza et al, 2007;Babu et al, 2008).…”

Differentially expressed stress-related genes in the compatible citrus-Citrus leprosis virus interaction

“…Numerous reports have indicated that carbohydrate metabolism in the source leaf is influenced by viral infection (Tecsi et al, 1994a(Tecsi et al, , 1994b(Tecsi et al, , 1996. Infected source leaves are usually characterized by a decrease in the concentration of soluble sugars, and often starch accumulation (Goodman et al, 1986;Fraser, 1987).…”